Display device

ABSTRACT

A display device includes a plurality of pixels each having a plurality of light-emitting regions including at least a first light-emitting region of a first color, a second light-emitting region of a second color, and a third light-emitting region of a third color and a light-transmitting region. Visibility of the first color is higher than visibility of the second color. The plurality of light-emitting regions are divided into a first group including the first light-emitting region and a second group including the second light-emitting region. The first light-emitting region is adjacent to the second light-emitting region. The light-transmitting region is located between the first light-emitting region and the second light-emitting region. The light-transmitting region is not located in a region between light-emitting regions adjacent to each other in the first group and in a region between light-emitting regions adjacent to each other in the second group.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority from Japanese applicationJP2016-135143 filed on Jul. 7, 2016, the content of which is herebyincorporated by reference into this application.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a display device.

2. Description of the Related Art

There has been known a so-called transparent display device thatdisplays an image on a display area and has a structure allowing theobject beyond the display device to be seen through. JP2012-238544Adiscloses a transparent display device in which adjacent threesub-pixels, including a red sub-pixel, a green sub-pixel, and a bluesub-pixel constitute one pixel, and the transparent display device has atransparent region (light-transmitting region) adjacent to the pixel(refer to FIG. 14(b) of JP2012-238544A). Further, JP2014-085384Adiscloses a pixel circuit and a driving method thereof in which aplurality of adjacent sub-pixels in a column direction share an outputswitch and a threshold voltage and variations in mobility of a drivetransistor of each sub-pixel are cancelled.

In recent years, transparency of transparent display devices is expectedto be enhanced. In order to enhance transparency, it can be consideredto increase a ratio of a light-transmitting region in a display area.Such a case, however, has the drawback that the number of pixels isdecreased and definition of images is declined.

SUMMARY OF THE INVENTION

One or more embodiments of the present invention have been conceived inview of the above, and an object thereof is to enhance transparency anddefinition of a display device having a light-transmitting region.

A display device according to one aspect of the present inventionincludes a plurality of pixels each having a plurality of light-emittingregions including at least a first light-emitting region of a firstcolor, a second light-emitting region of a second color, and a thirdlight-emitting region of a third color and a light-transmitting region,wherein visibility of the first color is higher than visibility of thesecond color, the visibility of the second color is higher thanvisibility of the third color, the plurality of light-emitting regionsare divided into a first group including the first light-emitting regionand a second group including the second light-emitting region, the firstlight-emitting region is adjacent to the second light-emitting region,the light-transmitting region is located between the firstlight-emitting region and the second light-emitting region, and thelight-transmitting region is not located in a region betweenlight-emitting regions adjacent to each other in the first group and ina region between light-emitting regions adjacent to each other in thesecond group.

A display device according to another aspect of the present inventionincludes a first pixel that includes a red sub-pixel, a green firstsub-pixel, a green second sub-pixel, and a blue sub-pixel, a secondpixel that is adjacent to the first pixel in a first direction andincludes a red sub-pixel, a green first sub-pixel, a green secondsub-pixel, and a blue sub-pixel, and a light-transmitting region throughwhich light transmits, wherein the first pixel includes a firstsub-pixel group that includes the blue sub-pixel and the green firstsub-pixel adjacent to each other in the first direction, and a secondsub-pixel group that includes the green second sub-pixel and the redsub-pixel adjacent to each other in the first direction and is adjacentto the first sub-pixel group in a second direction intersecting thefirst direction, the second pixel includes a third sub-pixel group thatincludes the green first sub-pixel and the red sub-pixel adjacent toeach other in the first direction, and a fourth sub-pixel group thatincludes the blue sub-pixel and the green second sub-pixel adjacent toeach other in the first direction and is adjacent to the third sub-pixelgroup in the second direction, wherein the first sub-pixel group and thethird sub-pixel group are arranged in the first direction, the secondsub-pixel group and the fourth sub-pixel group are arranged in the firstdirection, the light-transmitting region includes a first region thatincludes a region between the first sub-pixel group and the secondsub-pixel group and a region between the third sub-pixel group and thefourth sub-pixel group and extends in the first direction, a secondregion that includes a region between the first sub-pixel group and thethird sub-pixel group and a region between the second sub-pixel groupand the fourth sub-pixel group and extends in the second direction.

A display device according to another aspect of the present inventionincludes a first pixel that includes a red sub-pixel, a green sub-pixel,a white sub-pixel, and a blue sub-pixel, a second pixel that is adjacentto the first pixel in a first direction and includes a red sub-pixel, agreen sub-pixel, a white sub-pixel, and a blue sub-pixel, and alight-transmitting region through which light transmits, wherein thefirst pixel includes a first sub-pixel group that includes the whitesub-pixel and the blue sub-pixel adjacent to each other in the firstdirection; and a second sub-pixel group that includes the green secondsub-pixel and the red sub-pixel adjacent to each other in the firstdirection and is adjacent to the first sub-pixel group in a seconddirection intersecting the first direction, the second pixel includes athird sub-pixel group that includes the green sub-pixel and the redsub-pixel adjacent to each other in the first direction, and a fourthsub-pixel group that includes the white sub-pixel and the blue sub-pixeladjacent to each other in the first direction and is adjacent to thethird sub-pixel group in the second direction, wherein the firstsub-pixel group and the third sub-pixel group are aligned in the firstdirection, the second sub-pixel group and the fourth sub-pixel group arealigned in the first direction, the light-transmitting region includes afirst region that includes a region between the first sub-pixel groupand the second sub-pixel group and a region between the third sub-pixelgroup and the fourth sub-pixel group and extends in the first direction,a second region that includes a region between the first sub-pixel groupand the third sub-pixel group and a region between the second sub-pixelgroup and the fourth sub-pixel group and extends in the seconddirection.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic sectional view schematically illustrating across-sectional view of the display device around a pixel switchtransistor according to the present embodiments.

FIG. 2 is a schematic view illustrating a wiring structure of thedisplay device according to the present embodiments.

FIG. 3 is a diagram of an equivalent circuit per sub-pixel of an activematrix constituting the display device according to the presentembodiments.

FIG. 4 is a schematic view of a light-emitting region and alight-transmitting region in the display device according to the presentembodiments.

FIG. 5 is a schematic view of light-emitting regions andlight-transmitting regions of the display device according to themodifications of the present embodiments.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the present invention (hereinafter, referred to as thepresent embodiments) are described below with reference to theaccompanying drawings. The disclosure herein is merely an example, andappropriate modifications coming within the spirit of the presentinvention, which are easily conceived by those skilled in the art, areintended to be included within the scope of the invention as a matter ofcourse. In the accompanying drawings, widths, thicknesses, shapes, orother characteristics of each part are schematically illustratedcompared to actual configurations for clarity of illustration. However,such a schematic illustration is merely an example and not intended tolimit the present invention. In the present specification and drawings,some elements identical or similar to those shown previously are denotedby the same reference signs as the previously shown elements, and thusrepetitive detailed descriptions of them may be omitted as appropriate.

Further, in the present embodiments, when a positional relationshipbetween a component and another component is defined, the words “on” and“below” suggest not only a case where the another component is disposedimmediately on or below the component, but also a case where thecomponent is disposed on or below the another component with a thirdcomponent interposed therebetween.

FIG. 1 is a schematic sectional view schematically illustrating across-sectional view of the display device around a pixel switchtransistor according to the present embodiments. A display device 100 isa so-called transparent display device that displays an image on adisplay area A (see FIG. 2), while allowing an object beyond the displayarea A to be seen through. The display device 100 is a so-calledtop-emitting display device that takes out light from an organiclight-emitting diode 30 from a direction opposite to a substrate 10(R-arrow direction in FIG. 1), and an active-driving type OLED (OrganicLight Emitting Diode) display device.

As shown in FIG. 1, the display device 100 includes the substrate 10, apixel switch transistor SST, the organic light-emitting diode 30, a seal40, a filler 50, and a counter substrate 60, and has a structure inwhich these elements are laminated. In the present embodiments, theorganic light-emitting diode 30 is used as a light emitting element,although a quantum dot light-emitting element may also be used as alight emitting element.

The pixel switch transistor SST includes source/drain regions 21 and 22,a polysilicon layer 23, a gate line layer 25, and source/drainelectrodes 27. Further, a first insulating interlayer 24 is provided onthe polysilicon layer 23, and a second insulating interlayer 28 isprovided on the source/drain electrodes 27. A first base film 70 made ofa material such as silicon nitride (SiNx) is disposed between thesubstrate 10 and the pixel switch transistor SST so that an ion, such asnatrium and kalium, is not mixed into the polysilicon layer 23 and thegate line layer 25 from the substrate 10. A second base film 71 made ofsilicon oxide (SiOx) is disposed between the first base film 70 and thepolysilicon layer 23. An insulating film 80 is provided on the secondbase film 71.

The organic light-emitting diode 30 includes an organic EL (ElectroLuminescence) layer 31, a lower electrode 32 provided below the organicEL layer 31, and an upper electrode 33 provided on the organic EL layer31. One of the lower electrode 32 and the upper electrode 33 functionsas an anode, and the other functions as a cathode.

The organic EL layer 31 covers the lower electrode 32 in a region thatis to be the light-emitting region L (see FIG. 4), and is connected toone of the source/drain electrodes 27 through a hole penetrating thesecond insulating interlayer 28. A third insulating interlayer(hereinafter referred to as a bank) 90 is formed in a non-light emittingregion. The organic EL layer 31 is provided so as to cover the lowerelectrode 32, and separated from the lower electrode 32 in the non-lightemitting region by the bank 90. The upper electrode 33 is provided so asto cover the entire organic EL layer 31.

Here, the configuration of the organic EL layer 31 will be discussed.The configuration of the organic EL layer 31 is well known technology,and thus, is simplified in FIG. 1. The organic EL layer 31 is configuredby stacking an electron transport layer, alight emitting layer, and ahole transport layer, from the cathode side to the anode side in thisorder. A hole injection layer and a hole blocking layer may be disposedbetween the anode and the light emitting layer in addition to the holetransport layer. Further, an electron injection layer or an electronblocking layer may be disposed between the cathode and the lightemitting layer in addition to the electron transport layer. The lightemitting layer and the electron transport layer may be one layer made ofmaterials capable of serving their functions.

When a DC voltage is applied between the lower electrode 32 and theupper electrode 33, holes injected from the anode side reach the lightemitting layer through the hole transport layer, while electronsinjected from the cathode side reach the light emitting layer throughthe electron transport layer, and thus the electrons and the holes arerecombined. With the recombination of the electrons and the holes, theorganic light-emitting diode 30 emits light having a predeterminedwavelength. In order to efficiently utilize light emitted from the lightemitting layer, the lower electrode 32 is preferably made of a materialhaving a high light reflectance. The lower electrode 32 may beconfigured by laminating a transparent conductive film made of amaterial such as indium tin oxide (ITO) and a reflective film made of amaterial such as silver.

The seal 40 is formed so as to cover the upper electrode 33. The seal 40preferably has high gas barrier property so as to protect the organiclight-emitting diode 30 from water, for example, and is transparent tovisible light. For example, a dense inorganic layer, such as siliconoxide, or a laminated film of an inorganic layer and an organic layermay be used as the seal 40. The counter substrate 60 is formed on theseal 40 through the transparent filler 50 made of a polymeric material.

The counter substrate 60 includes a color filter 61, a black matrix BMdisposed around the color filter 61, and a transparent substrate 62disposed on the color filter 61. Although a glass substrate is used asthe substrate 10, it is not limited thereto and any substrate havinginsulation properties, such as a resin substrate, may be used.

Next, referring to FIGS. 2 and 3, an outline of a circuit configurationof the display device according to the present embodiments will bediscussed. FIG. 2 is a schematic view illustrating a wiring structure ofthe display device according to the present embodiments. FIG. 3 is adiagram illustrating an equivalent circuit per sub-pixel of an activematrix constituting the display device according to the presentembodiments.

In FIG. 2, a region surrounded by dashed lines on the substrate 10indicates a display area A, which displays an image. On the display areaA, a plurality of sub-pixels SP are disposed in a matrix. As shown inFIG. 2, a data driving circuit 110 that outputs an image signal to adata line D, a scan driving circuit 120 that outputs a scanning signalto a gate line G, and an output driving circuit 130 that drives anoutput switch transistor BCT are disposed around the display area A. Theoutput driving circuit 130 includes a reset switch transistor RST (seeFIG. 3) that is used common to the sub-pixels SP arranged in X-directionin FIG. 2. As described in details later, as shown in FIG. 2, the outputswitch transistor BCT is provided so as to be used common to twosub-pixels SP adjacent to each other in the X-direction.

As shown in FIG. 3, each sub-pixel SP includes a pixel switch transistorSST, an organic light-emitting diode 30, a storage capacitor Cs, a pixelcapacitor Cad, and a driver transistor DRT. The storage capacitor Cs andthe pixel capacitor Cad are condensers. The pixel capacitor Cad is anelement for controlling a light emission current amount, and is notneeded in some cases. In the pixel switch transistor SST, the gateelectrode is connected to the gate line G, one of the source/drainelectrodes is connected to the data line D, and the other one of thesource/drain electrodes is connected to the storage capacitor Cs. In thedriver transistor DRT, the gate electrode is connected to the storagecapacitor Cs, the source electrode is connected to a potential wiring E(see FIG. 2) through the output switch transistor BCT, and the drainelectrode is connected to one of electrodes of the organiclight-emitting diode 30. Further, the other one of the electrodes of theorganic light-emitting diode 30 is connected to current supply lines S1and S2 (see FIG. 2), which are used common to all sub-pixels SP, and isheld at a predetermined potential. The pixel switch transistor SST, thedriver transistor DRT, the output switch transistor BCT, and the resetswitch transistor RST are formed by the same conductivity type thin-filmtransistors, such as n-channel type thin-film transistors.

In the pixel circuit of the sub-pixel SP shown in FIG. 3, the drivertransistor DRT and the output switch transistor BCT are connected to theorganic light-emitting diode 30 in series between a high-potential powersupply line SLa and a low-potential power supply line SLb, and the gateelectrode is connected to a scanning line Sga. The driver transistor DRTincludes a source electrode connected to the organic light-emittingdiode 30, a drain electrode connected to a reset wiring Sgr, and a gateelectrode. The output switch transistor BCT switches drain electrodes ofthe high-potential power supply line SLa and the driver transistor DRTto a conducting state or a non-conducting state.

The pixel switch transistor SST is connected the data line D and thegate electrodes of the driver transistor DRT, and switches whether tocapture a video signal Vsig, which is transmitted through the data lineD, into the gate electrode of the driver transistor DRT. The capturedsignal is stored in the storage capacitor Cs.

The two adjacent sub-pixels SP in the X-direction share the outputswitch transistor BCT (see FIG. 2). This enables to reduce to half ofthe number of the output switch transistor BCT and reduce light-shieldedarea, compared to a case where each sub-pixel SP is provided with anoutput switch transistor BCT, and thus it is possible to provide adisplay device having higher transparency.

When a display is performed with a known driving method in the sub-pixelcircuit configuration described above, an output current given to theorganic light-emitting diode has a value that does not depend on athreshold voltage of the driver transistor DRT. Further, the effect ofthe mobility of the driver transistor DRT can be compensated. As such,display defect caused by characteristic variance in the drivertransistor DRT, streak-like irregularities, and roughness are prevented,and high-quality image display is enabled with three or less number oftransistors per sub-pixel. In this case, the smaller number oftransistors can reduce an area shielded from light by the transistorsand the surrounding wiring, and thus it is possible to provide a displaydevice having higher transparency.

FIG. 4 is a schematic view of the light-emitting region and thelight-transmitting region in the display device according to the presentembodiments. The display device 100 includes a plurality of pixels Parranged in a matrix on the display area A and a light-transmittingregion M. In a case where light-emitting regions need to bedistinguished, alight-emitting region is described with, for example, anumber (1,2) indicating a group number or an alphabet letter (W,B,G,R)indicating a color in addition to “L” indicating a light-emittingregion. In a case where light-emitting regions do not need to bedistinguished, a light-emitting region is simply described as alight-emitting region L. The same applies to pixels P,light-transmitting regions M, and wirings W.

A pixel P is formed of a plurality of light-emitting regions L having atleast three luminescent colors. In the present embodiments, as shown inFIG. 4, a pixel P is formed of four-color light-emitting regions dividedinto a light-emitting region LW with white luminescent color, alight-emitting region LB with blue luminescent color, a light-emittingregion LG with green luminescent color, and a light-emitting region LRwith red luminescent color. The light-emitting regions LW, LB, LG, andLR are regions in which sub-pixels SP respectively disposed incorresponding light-emitting regions are controlled in brightness andemit light.

The present embodiments employ a color filter method in which alllight-emitting regions L emit the same color (e.g., white), and onlylight having a predetermined wavelength transmits each light-emittingregion L through a color filter 61 provided in a counter substrate 60,but not limited to this. The present embodiments may employ acolor-separation method for splitting the organic EL layer 31 to emitlight of colors according to luminescent colors of the respectivelight-emitting regions L.

The light-emitting region L is a region divided by wirings W, and hassub-pixels SP arranged therein. The light-transmitting region M is anopening region divided by wirings W, and allows an object beyond thedisplay area device A to be seen through. The wirings shown in FIG. 4are, for example, the gate line G and the data line D described byreferring to FIGS. 2 and 3, although any type of wiring may be used. Assuch, a wiring extending in the X-direction (first direction) isdescribed as a wiring WX, and a wiring extending in the Y-direction(second direction) perpendicular to the X-direction is described as awiring WY. As shown in FIG. 4, n wirings WX (n is an integer) arearranged in the Y-direction, and m wirings WY (m is an integer) arearranged in the X-direction.

In each pixel P, light-emitting regions L are divided intolight-emitting regions of a first group L1 and light-emitting regions ofa second group L2. In the present embodiments, light-emitting regions LWand light-emitting regions LB are light-emitting regions of a firstgroup L1, and light-emitting regions LG and light-emitting regions LRare light-emitting regions of a second group L2.

In the present embodiments, the top two light-emitting regions L in thevisibility of luminescent colors are respectively included in the firstgroup L1 and the second group L2. In the light-emitting regions LW, LB,LG, and LR, respectively in white, blue, green, and red colors, theluminescent colors of the top two light-emitting regions in thevisibility are white and green. As such, the light-emitting region LWhaving a white luminescent color belongs to the first group L1, and thelight-emitting region LG having a green luminescent color belongs to thesecond group L2. In this regard, the visibility indicates a degree towhich a person feels brightness, and light having about 550 nmwavelength is known to have high visibility.

On the other hand, in the light-emitting regions LW, LB, LG, and LR,respectively in white, blue, green, and red colors, the luminescentcolors of the lowest two light-emitting regions in the visibility areblue and red. These two lowest light-emitting regions LB and LR in thevisibility are respectively combined with the top two light-emittingregions LW and LG in the visibility, and this enables to provide enoughvisibility in both of the first group L1 and the second group L2.Specifically, the blue light-emitting region LB is provided in the firstgroup L1 so as to be adjacent to the white light-emitting region LW inthe X-direction, and the red light-emitting region LR is provided in thesecond group L2 so as to be adjacent to the green light-emitting regionLG in the X-direction.

Further, the display device 100 includes at least a light-transmittingregion M formed in a region between the light-emitting regions LW and LBin the first group L1 and the light-emitting regions LG and LR in thesecond group L2. In the present embodiments, the light-transmittingregion M is formed so as to surround the light-emitting regions LW andLB in the first group L1 and the light-emitting regions LG and LR in thesecond group L2. That is, in FIG. 4, a region other than thelight-emitting region L and the wiring W is the light-transmittingregion M. In another viewpoint, it can be said that the L-shapedlight-transmitting region M is disposed around the light-emittingregions L forming one group. For example, as shown in FIG. 4, it can besaid that the L-shaped light-transmitting region M, which includes thelight-transmitting region M1 adjacent to the light-emitting region LG inthe X-direction, the light-transmitting region M2 adjacent to thelight-transmitting region M1 in the Y-direction, the light-transmittingregion M3 adjacent to the light-transmitting region M2 in theX-direction, and the light-transmitting region M4 adjacent to thelight-transmitting region M3 in the X-direction, is disposed around thelight-emitting regions LG and LR of the second group L2 of the pixel P2.This structure enables to increase a ratio of a light-transmittingregion M in one pixel P, and thus improvement in transparency can beexpected.

In the present embodiments, a light-emitting region LW and alight-emitting region LB are arranged in the X-direction in any pixel P(e.g., P1, P2, P3) in the light-emitting regions in the first group L1.Similarly, a light-emitting region LG and a light-emitting region LR arearranged in the X-direction in any pixel P in the light-emitting regionsin the second group L2. In this way, the light-emitting regions Ladjacent to each other in the same group have luminescent colorsdifferent from each other. Further, in the pixels P (P1,P2) adjacent toeach other in the X-direction, the light-emitting regions LW and LB inthe first group L1 and the light-emitting regions LG and LR in thesecond group L2 are placed so as to oppose to each other in theY-direction. That is, the light-emitting regions LW and LB in the firstgroup L1 of the pixel P1 are arranged in the X-direction to be adjacentto the light-emitting regions LG and LR in the second group L2 of thepixel P2, and the light-emitting regions LG and LR in the second groupL2 of the pixel P1 are arranged in the X-direction to be adjacent to thelight-emitting regions LW and LB in the first group L1 of the pixel P2.The adjacent light-emitting regions L respectively included in theadjacent pixels P are constructed to have luminescent colors differentfrom each other. In other words, the light-emitting region LB of thepixel P1 is arranged in the X-direction to be adjacent to thelight-emitting region LG of the pixel P2, and the light-emitting regionLR of pixel P1 is arranged in the X-direction to be adjacent to thelight-emitting region LW of the pixel P2.

As described above, in the present embodiments, light-transmittingregions M are disposed between the light-emitting regions LW and LB inthe first group L1 and the light-emitting regions LG and LR in thesecond group L2, which form one pixel P. This structure enables toincrease a ratio of light-transmitting regions M in the display area A,and thus improvement in transparency can be expected. Further, white,blue, green, and red light-emitting regions LW, LB, LG, and LR formingone pixel P are divided into two groups for placement, and thusimprovement in definition of an image can be expected. In addition, awhite light-emitting region LW having high visibility is placed in thefirst group L1, and a green light-emitting region LG having lowvisibility is placed in the second group L2, and thus enough visibilitycan be obtained in both of the groups. In other words, enough visibilitycan be obtained throughout the display area A. When an image isdisplayed, known sub-pixel rendering is performed based on an imagesignal so that each of a white sub-pixel having high visibility and agreen sub-pixel having high visibility corresponds to one pixel, andthus it is possible to enhance effective definition of the imageperceived by the human eye. As such, the transparent display devicehaving high definition of the image and high transparency can beprovided.

In the present embodiments, the light-transmitting regions M are formedso as to surround the light-emitting regions LW and LB in the firstgroup L1 and the light-emitting regions LG and LR in the second groupL2, but not limited to this. The light-transmitting regions M may beformed so as to at least avoid a region between the light-emittingregion LW and the light-emitting region LB, which are adjacent to eachother in the first group L1, a region between the light-emitting regionLG and the light-emitting region LR, which are adjacent to each other inthe second group L2, and a region between the light-emitting regions LWand LB in the first group L1 and the light-emitting regions LG and LR inthe second group L2.

Here, in the light-transmitting regions M, there is a case wherediffraction of light is caused by influence of edges of the wirings WXand WY. In particular, when regions are divided by the wirings WX and WYat regular intervals, that is, when the wirings WX and WY are arrangedwith a constant period (integral multiple), strong diffraction of lightoccurs. When the strong diffraction of light occurs, the light isscattered and the visibility is reduced. In the present embodiments, thelight-transmitting regions M are divided in multiple regions ofdifferent widths so that different periods are mixedly used.

Specifically, when the width between the wiring WY1 and the wiring WY2is l1, the width between the wiring WY2 and the wiring WY3 is l2, andthe width between the wiring WY3 and the wiring WY4 is l3, l1=l2<l3. Inthis way, it is possible to prevent the diffraction of light from beingstrong and the visibility from being reduced by differentiating thewidth of l3 from the width of l1 and the width of l2. This is notlimited thereto. For example, it is possible to further prevent thediffraction of light from being strong by differentiating the width ofl1 from the width of l2. In the present embodiments, the width of l3 isgreater than twice the width of l1 and the width of l2, and less thanthree times the width of l1 and the width of l2 so that the width of l3is not an integral multiple of the width of l1 and the width of l2.

Similarly, when the width between the wiring WX1 and the wiring WX2 ish1, the width between the wiring WX2 and the wiring WX3 is h2, and thewidth between the wiring WX3 and the wiring WX4 is h3, h1=h3<h2. In thisway, it is possible to prevent the diffraction of light from beingstrong by differentiating the width of h2 from the width of h1 and thewidth of h3. This is not limited thereto. For example, it is possible tofurther prevent the diffraction of light from being strong bydifferentiating the width of h1 from the width of h3. In the presentembodiments, the width of h2 is greater than twice the width of h1 andthe width of h3, and less than three times the width of h1 and the widthof h3 so that the width of h2 is not an integral multiple of the widthof h1 and the width of h3.

The light-transmitting region M needs to allow an object beyond thedisplay area A to be seen through, while a transistor provided on eachsub-pixel SP needs to avoid projecting from the light-emitting region Land being provided on the light-transmitting region M. In particular, inthe present embodiments, the light-emitting regions L forming one pixelP are divided into two groups, and thus a size of light-emitting regionsL collectively disposed is reduced. As such, some consideration isneeded regarding the arrangement of the transistors so that thetransistors do not project from the light-emitting regions L.

In the present embodiments, as shown in FIG. 3, an output switchtransistor BCT is used common to two light-emitting regions L(sub-pixels SP). In other words, the output switch transistor BCT (firsttransistor), which is used common to the light-emitting region LW andthe light-emitting region LB in the first group L1, is provided.Similarly, an output switch transistor BCT (second transistor), which isused common to the light-emitting region LG and the light-emittingregion LR in the second group L2, is provided. Such structures enable toreduce the number of transistors in one light-emitting region L, therebyplacing the transistors within the light-emitting region L and ensuringthe transparency of the light-transmitting region M. In the presentembodiments, the case is explained in which the output switch transistorBCT is used common to two light-emitting regions L, but is not limitedto this. Further transparency is achieved by using a transistor usedcommon to three or more light-emitting regions L.

Next, the display device according to modifications of the presentembodiments (hereinafter simply referred to as modifications) will bediscussed. FIG. 5 is a schematic view of light-emitting regions andlight-transmitting regions of the display device according to themodifications. The display device according to the modifications is thesame as the display device 100 described by referring to FIGS. 1 to 4except the luminescent colors and arrangement of the light-emittingregions L. As such, explanation of the same elements will be omitted.

As shown in FIG. 5, in the modifications, a pixel P is formed of fourlight-emitting regions LB, LG, LG, and LR in three luminescent colors ofblue, green, and red. In these four light-emitting regions, both of thetop two light-emitting regions L in the visibility have luminescentcolors of green. As such, the light-emitting regions in the first groupL1 include the light-emitting region LB having a luminescent color ofblue and the light-emitting region LG having a luminescent color ofgreen, and the light-emitting regions in the second group L2 include thelight-emitting region LG having a luminescent color of green and thelight-emitting region LR having a luminescent color of red. In this way,a green light-emitting region LG having the high visibility is providedin each of the groups, thereby providing enough visibility.

In the modifications, similarly to the present embodiments described byreferring to FIG. 4, a light-emitting region LB and a light-emittingregion LG in a first group L1 are aligned in the X-direction in anypixel P (e.g., P1, P2, P3). Similarly, a light-emitting region LG and alight-emitting region LR in a second group L2 are aligned in theX-direction in any pixel P. In this way, light-emitting regions Ladjacent to each other in the same group have different luminescentcolors. Further, in the pixels P (P1,P2) adjacent to each other in theX-direction, the light-emitting regions LB and LG in the first group L1and the light-emitting regions LG and LR in the second group L2 areplaced so as to oppose to each other in the Y-direction. That is, thelight-emitting regions LB and LG in the first group L1 of the pixel P1are adjacent in the X-direction to the light-emitting regions LG and LRin the second group L2 of the pixel P2, and the light-emitting regionsLG and LR in the second group L2 of the pixel P1 are adjacent in theX-direction to the light-emitting regions LB and LG in the first groupof the pixel P2. The light-emitting regions L, which are adjacent toeach other and included in respective pixels P adjacent to each other,have luminescent colors different from each other.

In the present embodiments, the arrangement order and luminescent colorsof the light-emitting regions L are not limited to the examples shown inFIGS. 4 and 5, but may be constructed to have enough visibility inlight-emitting regions in each group.

While there have been described what are at present considered to becertain embodiments of the invention, it will be understood that variousmodifications may be made thereto, and it is intended that the appendedclaim cover all such modifications as fall within the true spirit andscope of the invention.

What is claimed is:
 1. A display device comprising: a plurality ofpixels each having a plurality of light-emitting regions including atleast a first light-emitting region of a first color, a secondlight-emitting region of a second color, and a third light-emittingregion of a third color; and a light-transmitting region, whereinvisibility of the first color is higher than visibility of the secondcolor, the visibility of the second color is higher than visibility ofthe third color, the plurality of light-emitting regions are dividedinto a first group including the first light-emitting region and asecond group including the second light-emitting region, the firstlight-emitting region is adjacent to the second light-emitting region,the light-transmitting region is located between the firstlight-emitting region and the second light-emitting region, and thelight-transmitting region is not located in a region betweenlight-emitting regions adjacent to each other in the first group and ina region between light-emitting regions adjacent to each other in thesecond group.
 2. The display device according to claim 1, wherein thelight-transmitting region surrounds the light-emitting regions in thefirst group and the light-emitting regions in the second group.
 3. Thedisplay device according to claim 1, further comprising a plurality oftransistors that respectively correspond to the plurality of pixels,wherein the plurality of transistors include a first transistor commonto the light-emitting regions in the first group, and a secondtransistor common to the light-emitting regions in the second group. 4.The display device according to claim 1, wherein the first color isgreen and the second color is white.
 5. The display device according toclaim 1, wherein the plurality of light-emitting regions including afourth first light-emitting region of the first color, the first coloris green, and the fourth light-emitting is included in the second group.6. The display device according to claim 1, wherein the plurality ofpixels includes a first pixel and a second pixel adjacent to the firstpixel, the first pixel has one light-transmitting region, the secondpixel has another light-transmitting region adjacent to the onelight-transmitting region, a color emitted by the one light-transmittingregion is different from a color emitted by the anotherlight-transmitting region.
 7. The display device according to claim 1,wherein the light-emitting regions in the first group have the samecombination of the luminescent colors and are arranged in a firstdirection in any of the plurality of pixels, the light-emitting regionsin the second group have the same combination of the luminescent colorsand are arranged in the first direction in any of the plurality ofpixels, the light-emitting regions in the first group and thelight-emitting regions in the second group are arranged in a seconddirection perpendicular to the first direction, and in the pixelsadjacent to each other in the first direction, the light-emittingregions in the first group and the light-emitting regions in the secondgroup are placed so as to oppose to each other in the second direction.8. The display device according to claim 7, wherein the light-emittingregions in the first group have the same arrangement order of theluminescent colors in any of the plurality of pixels, and thelight-emitting regions in the second group have the same arrangementorder of the luminescent colors in any of the plurality of pixels. 9.The display device according to claim 1, wherein at least one of theplurality of pixels includes a first sub-pixel and a second sub-pixeladjacent to the first sub-pixel, each of the first sub-pixel and thesecond sub-pixel includes an organic light-emitting diode and a pixelcircuit, the pixel circuit comprises: a driver transistor connected tothe organic light-emitting diode through one of source/drain electrodesof the driver transistor; a pixel switch transistor connected to a gateelectrode of the driver transistor through one of source/drainelectrodes of the pixel switch transistor; and an output switchtransistor connected to an other of the source/drain electrodes of thedriver transistor through one of source/drain electrodes the outputswitch transistor, and the output switch transistor is common to thefirst sub-pixel and the second sub-pixel.
 10. A display devicecomprising: a first pixel that includes a red sub-pixel, a green firstsub-pixel, a green second sub-pixel, and a blue sub-pixel; a secondpixel that is adjacent to the first pixel in a first direction andincludes a red sub-pixel, a green first sub-pixel, a green secondsub-pixel, and a blue sub-pixel; and a light-transmitting region throughwhich light transmits, wherein the first pixel comprises: a firstsub-pixel group that includes the blue sub-pixel and the green firstsub-pixel adjacent to each other in the first direction; and a secondsub-pixel group that includes the green second sub-pixel and the redsub-pixel adjacent to each other in the first direction and is adjacentto the first sub-pixel group in a second direction intersecting thefirst direction, the second pixel comprises: a third sub-pixel groupthat includes the green first sub-pixel and the red sub-pixel adjacentto each other in the first direction; and a fourth sub-pixel group thatincludes the blue sub-pixel and the green second sub-pixel adjacent toeach other in the first direction and is adjacent to the third sub-pixelgroup in the second direction, wherein the first sub-pixel group and thethird sub-pixel group are arranged in the first direction, the secondsub-pixel group and the fourth sub-pixel group are arranged in the firstdirection, the light-transmitting region comprises: a first region thatincludes a region between the first sub-pixel group and the secondsub-pixel group and a region between the third sub-pixel group and thefourth sub-pixel group and extends in the first direction, a secondregion that includes a region between the first sub-pixel group and thethird sub-pixel group and a region between the second sub-pixel groupand the fourth sub-pixel group and extends in the second direction. 11.The display device according to claim 10, wherein the green firstsub-pixel of the first sub-pixel group opposes to the green firstsub-pixel of the third sub-pixel group, and the red sub-pixel of thesecond sub-pixel group opposes to the blue sub-pixel of the fourthsub-pixel group.
 12. The display device according to claim 10, whereinthe first region intersects the second region between the first pixeland the second pixel.
 13. A display device comprising: a first pixelthat includes a red sub-pixel, a green sub-pixel, a white sub-pixel, anda blue sub-pixel; a second pixel that is adjacent to the first pixel ina first direction and includes a red sub-pixel, a green sub-pixel, awhite sub-pixel, and a blue sub-pixel; and a light-transmitting regionthrough which light transmits, wherein the first pixel comprises: afirst sub-pixel group that includes the white sub-pixel and the bluesub-pixel adjacent to each other in the first direction; and a secondsub-pixel group that includes the green second sub-pixel and the redsub-pixel adjacent to each other in the first direction and is adjacentto the first sub-pixel group in a second direction intersecting thefirst direction, the second pixel comprises: a third sub-pixel groupthat includes the green sub-pixel and the red sub-pixel adjacent to eachother in the first direction; and a fourth sub-pixel group that includesthe white sub-pixel and the blue sub-pixel adjacent to each other in thefirst direction and is adjacent to the third sub-pixel group in thesecond direction, wherein the first sub-pixel group and the thirdsub-pixel group are aligned in the first direction, the second sub-pixelgroup and the fourth sub-pixel group are aligned in the first direction,the light-transmitting region comprises: a first region that includes aregion between the first sub-pixel group and the second sub-pixel groupand a region between the third sub-pixel group and the fourth sub-pixelgroup and extends in the first direction, a second region that includesa region between the first sub-pixel group and the third sub-pixel groupand a region between the second sub-pixel group and the fourth sub-pixelgroup and extends in the second direction.
 14. The display deviceaccording to claim 13, wherein the blue sub-pixel of the first sub-pixelgroup opposes to the green sub-pixel of the third sub-pixel group, andthe red sub-pixel of the second sub-pixel group opposes to the whitesub-pixel of the fourth sub-pixel group.
 15. The display deviceaccording to claim 13, wherein the first region intersects the secondregion between the first pixel and the second pixel.